The present invention relates to a hard disk drive or other disk drive containing a disc-shaped recording medium.
In recent years, hard disk drives have been incorporated in various apparatuses. Hard disk drives are mounted, for instance, in a mobile music player and car navigation system. Under these circumstances, a shingle write method is used as a technology for increasing the information recording capacity while reducing the hard disk drive size. In the shingle write method, data tracks are recorded in a shingling manner, for instance, from the inner circumferential end of a recording medium to the outer circumferential end while performing a partial overwrite with a neighboring data track. This ensures that the widths of the resultant data tracks are smaller than the actual write widths of a magnetic head.
However, when the above method is used to write data on the k-th data track from the innermost circular end, it is necessary to rewrite the k-th to outermost data tracks. Under these circumstances, a technology for reducing the rewrite overhead is disclosed by Patent Document 1 (U.S. Pat. No. 6,185,063).
The technology disclosed by Patent Document 1 arranges the data tracks into groups of two as shown in FIG. 7 and uses such data track groups to perform a shingle write. This technology records the inner data track, which is contained in a group of two data tracks, and then records the outer data track. The outer data track is not partly overwritten but is used as a data track having the magnetic head write width.
When the above method is used in a situation where an odd-numbered data track and even-numbered data track differ in the read position, the read position can be set while avoiding a data track pair overwrite portion (overlap) (see FIG. 10 in Patent Document 1 ). Therefore, the data can be rewritten with relative flexibility.